linux-kernel - Re: [PATCH 14/16] x86/mm/legacy: Populate the user page-table with user pgd's

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 17 Jan 2018 15:41:07 -0800
From:   Andy Lutomirski <luto@...nel.org>
To:     Joerg Roedel <joro@...tes.org>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...nel.org>,
        "H . Peter Anvin" <hpa@...or.com>, X86 ML <x86@...nel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Linux-MM <linux-mm@...ck.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Andy Lutomirski <luto@...nel.org>,
        Dave Hansen <dave.hansen@...el.com>,
        Josh Poimboeuf <jpoimboe@...hat.com>,
        Juergen Gross <jgross@...e.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Borislav Petkov <bp@...en8.de>, Jiri Kosina <jkosina@...e.cz>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        Brian Gerst <brgerst@...il.com>,
        David Laight <David.Laight@...lab.com>,
        Denys Vlasenko <dvlasenk@...hat.com>,
        Eduardo Valentin <eduval@...zon.com>,
        Greg KH <gregkh@...uxfoundation.org>,
        Will Deacon <will.deacon@....com>,
        "Liguori, Anthony" <aliguori@...zon.com>,
        Daniel Gruss <daniel.gruss@...k.tugraz.at>,
        Hugh Dickins <hughd@...gle.com>,
        Kees Cook <keescook@...gle.com>,
        Andrea Arcangeli <aarcange@...hat.com>,
        Waiman Long <llong@...hat.com>, Joerg Roedel <jroedel@...e.de>
Subject: Re: [PATCH 14/16] x86/mm/legacy: Populate the user page-table with
 user pgd's

On Tue, Jan 16, 2018 at 8:36 AM, Joerg Roedel <joro@...tes.org> wrote:
> From: Joerg Roedel <jroedel@...e.de>
>
> Also populate the user-spage pgd's in the user page-table.
>
> Signed-off-by: Joerg Roedel <jroedel@...e.de>
> ---
>  arch/x86/include/asm/pgtable-2level.h | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/arch/x86/include/asm/pgtable-2level.h b/arch/x86/include/asm/pgtable-2level.h
> index 685ffe8a0eaf..d96486d23c58 100644
> --- a/arch/x86/include/asm/pgtable-2level.h
> +++ b/arch/x86/include/asm/pgtable-2level.h
> @@ -19,6 +19,9 @@ static inline void native_set_pte(pte_t *ptep , pte_t pte)
>
>  static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
>  {
> +#ifdef CONFIG_PAGE_TABLE_ISOLATION
> +       pmd.pud.p4d.pgd = pti_set_user_pgd(&pmdp->pud.p4d.pgd, pmd.pud.p4d.pgd);
> +#endif
>         *pmdp = pmd;
>  }
>

Nothing against your patch, but this seems like a perfectly fine place
to rant: I *hate* the way we deal with page table folding.  Grr.